Matrox Marvel G400-TV Review

Environment Mapped Bump Mapping

Bumps

Originally invented by BitBoys, Environment Mapped Bump Mapping has made its way into Microsoft's DirectX 6, and the Matrox G400 is the first chip to implement hardware support for DX6's Environment Mapped Bump Mapping.

Environment Mapped Bump Mapping basically uses lighting and shading effects to simulate surface depths. When you look straight down at a bump, what makes you think, "hey that's a bump!" It's the lighting. If the light source is right above the bump, and you're looking down at the bump, the top of the bump will be bright because it will reflect the most light back to your eyes. The edges will be darker and give you a sense of depth because they don't reflect as much light.

EMBM uses a bump map to define elevations or depressions with different shades of colors. Then an environment map is applied over the bump map to supply all the special lighting features.

The T&L threat

Matrox is quick to refute claims that hardware T&L was going to make EMBM obsolete. The T&L camp argues that you can create the same EMBM effects such as rippling water or simulated surface imperfections with the brute force triangle method. Granted, using hundreds of thousands or millions of triangles to build a rippling ocean would be better than anything EMBM can do, but even with hardware T&L, the triangle throughput isn't large enough to make it a viable option. You can consider EMBM to be a nice shortcut that saves on the triangle costs.

Matrox is actively working with game developers to include EMBM support in upcoming games. Software EMBM support is also very easy to implement. It can be added into games after they've been released. We've seen EMBM support and EMBM patches for many of the new games on the market. Currenty, Matrox is running a game of the week campaign where it announces a new game is supporting the G400's EMBM and/or DualHead technology every week.

Without Environment Mapped Bump Mapping...

With Environment Mapped Bump Mapping

There are currently over 40 titles with EMBM support. Here's the list: